Furnace



Mwah 2, w33. L. A. MEKLER FURNAGE Filed Oct. 22, 1927 Patented Mar. 21, 1933 Y UNITED STATES PTENT OFFICE LEV A. MEKLEB, F CHICAGO, ILLINOS, ASSIGNOB T0 UNIVERSAL OIL PRODUCTS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTE'DAKOTA Application led October 22, 1927. Serial No. 228,016.

r1`his invention relates to improvements in furnaces, and refers more particularly to a furnace wherein hydrocarbon oil to be heated may be passed through a heating coil in heat interchange with the gases of combustion.

An object of this invention is to rovide an ecient method and means of eating wherein it is possible to control the amount of heating done in an portion of the furnace by regulating die quantity of the products of combustion passing through the dierent portions of the furnace.

. Another object of the present invention is to control the amount of heat absorbed by diderent portions of thev heat absorbing medium by the recirculation of regulated portions of the used gases of combustion to the heat generating zone.

The present invention is particularly applicable to the heating of hydrocarbon oil where said oil passes throu h the heating zone in an elongated conduit of restricted cross section, althou h it is to be understood, as above set forth, t at the invention in its broader aspects is not to be limited to this particular field.

.lhe utility of the invention as well as other objects and advantages will be more particularly apparent from the following description.

In the drawin Fig. 1 is a vertical sectional view of a mace built in accordance with the present invention.

Fig. 2 is a fragmentary vertical sectional view of a slightly modified form of a furnace built in accordance with the present invention. l

Referring more in detail to the draw' ,i 1 designates the outer shell or casing wliili may be constructed of the usual material for furnaces such as brick. Any suitable fuel such as oil or gas for instance may be introduced to the burner 2 and burned in the chamber 3. A heating chamber 4 may be provided in which may be mounted the tubes 5 which may be connected into a continuous coil through which the material to be heated may be passed. Passages 6 and 7 and ports 8 and 9 controlled by dampers 10 and 11 respectively may be provided to convey the products of combustion from chamber 3 to heating chamber 4. Flues 12 and 13 controlled by dampers 14. and 15 respectively may be provided for the recirculation of the gases of combustion. Flue 16 communicates with stack 17 whichis controlled by damper 18.

The fuel which may be either a powdered solid, liquid or agas, may be introduced to the burner 2 and injected with the proper amount of air into the combustion chamber 3 where it may be burned. The gases of combustion pass through the flue 6 into the chamber 7 from which they enter the heating chamber 4 through either or both of the ,ports 8 and 9. By manipulating dam ers 10 and 11 all or any regulated portion o the gases may be passed through either or both of the ports 8 and 9. Thus I may completely close damper 11 and cause all the hot gases to pass through port 8 whereby they contact the upper portion A of coil 5 in the chamber 4. Dampers 1a and 15 may be closed and the gases will pass over the lower portion B of coil 5, through iues 21 and 16 and out of the stack 17. This form of operation is similar to that of the conventional type of furnace.

If the greater part of the heating is desired on the upper portion A of coil 5, dampers 11 and 15 may be closed and damper 14 in. the recirculating flue opened. The hot gases will then enter chamber 4 through ports 8 and pass over the A portion of coil 5, a portion of them being drawn by the induction induced by the spray of burner 2 into recirculating flue 12, through the passage between wall 1 of the furnace wall 19 of the combustion chamber 3 and through opening 20 into the combustion zone where they are recirculated throughI the heating chamber 4. The proportion of the gases passing over the lower portion B' of coil 5, through ues 21 and 16, and out stack 17` may be controlled by damper 18 which regulates the pull ofthe stack 17 By opening damper 15 and partly closing damper 14 some of the gases may be recirculated after they have passed the lower portion B of coil 5, thus increasing the amount of heating accomplished in the lowu er ortion of the coil.

case it'may be desirable to accomplish the eater part of the heating in the lower portion of the coil 5, damper 14 may be closed and damper 15 opened. By closing ports 8 by means of damper 10 and opening ports 9 by means of damper 11 the 'ses will not pass over the upper portion o coil 5, but will all pass over the lower portion or the coil 5. The proportion of gases recirculated may be determined by rnanipulatin damper 15 and controlling the pull of stac 17 by means of damper 18.

Any portion of the gas may be caused to pass over the upper portion of coil 5 by manipulating dam rs 10 and 11,

As an example o the operation of the furnace, I will assume that 1000 pounds of fresh products of combustion are produced by the burning of the fuel introduced through the burner 2 and that the spray of the burner is able to induce and recirculate 2000 pounds of the spent products of cornbustion. Assuming the dampers in the recirculating liues are opened, a total of 3000 pounds of combustion products may therefore pass over the A portion of the coil 5. If the damper 14 is closed 3000 pounds of products of combustion, somewhat cooled b the passage over the A portion of the coil will also pass over the B portion of the coil and the recirculated gases will be drawn in after haring passed over all the coil 5 through recirculating ues 13 and 12 and then into the combustion chamber 3. If the damper 15 is closed and damper 14 opened, then while 3000 pounds of combustion products pass over the A portion of coil 5, only 1000 pounds of combustion products will pass over the B portion of coil 5. In this case the heat appliedto the B portion or' the coil will be substantially one-third of that applied in the operation with damper 14 closed and damper 15 open. By manipulating dempers 14 and 15 any amount of heating from one-third of the total up to the possible total can be accomplished in the B portion of coil 5 without substantially changing the heating effect on the A portion of coil 5.

A similar control may be effected upon the A portion of coil 5 by proper manipulation of the dampers as will be apparent to those skilled in the art.

It is thus apparent that by manipulation of the dampers any heating effect may be accomplished in the heating chamber 4. Any amount of the fresh gases may be passed over any portion or all of the coil 5, while at the same time the recirculated gases may be so controlled as to pass over any portion or all of coil 5. r1"hus the ma- I terial to he heated may he subjected to a gradual increase in temperature as it Hows through the coil 5 and then raised quickly to a high temperature just before it leaves the furnace. 0r if desired, the material may be quickly heated upon entering the furnace and then maintained at a desired temperature during the balance of its travel through the furnace;

it is to be understood that instead of inducing the recirculation ci the gases by means of the spray from the burner, a blower 1Q' may be employed in the manner il'- lustrated in Fig. 2.

It is obvious that the gases may be drawn from the heating chamber for recirculation at more than two points and in such a manner as to produce any desired heating effect on a given portion of the heating medium.

While I have shown in the drawing a furnace wherein the heat exchange between the combustion gases and the material to be' heated through the coils is effected while the combustion ases are passed in a downward direction, 1f desired, a similar desi involving'the features and principles of tne invention may be utilized wherein the combustion gases heat the liquid while said gases ascend. In other words the gases of combustion vand material to be heated may flow either in concurrent or countercurrent travel.

The coil within the chamber 4 may divided into two or more separate umts each having a separate inlet and outlet. Thus, materlal requiring a relatively lar e amount of heating may be passed throng one section, and material requiring a rea-tively small amount or heating may be passed t "ough the other section, the 'dow of the gases being regulated to accomplish heating eects.

claim as my invention:

1. A furnace comprising in combination, a heat generating zone, a heating zone communicating therewith through which me terial to be heated is passed, means for introducing and controlling the introduction of the heated gases generated in the heat generating zone into said heating zone comprising separated valve controlled dues communicating with said heating zone at separated points, means for recirculating regulated portions of the gases irom the heating zone to the heat generating zone, and means for controlling such recirculation comprising a plurality of recirculating dues independently controlled communicating with said heating zone at separated points.

2. A furnace comprising in combination, a heat generating zone, a heating zone communicsting therewith, tubular conduits located in said heating zone having inlet and outlet through which material to be heated is passed, iiues disposed to introduce the hot gases of combustion to any selected portion or all of said tubular structure, means or 

